1. Field of the Invention
This invention is in the field of wristwatches and more particularly wristwatches with removable watch faces.
2. Prior Art
It is known that wristwatches are one of the most commonly used devices in the world, and it is further known that for many persons a wristwatch is not only a timepiece but also is an accessory of dress and even a fashion statement. In the latter regard, it is desirable not only that a wristwatch be highly attractive, but also be one that coordinates or harmonizes with the other articles of dress, such as a person""s suit, shirt or jewelry.
While some persons wear the same watch for all occasions and with all different attire, either because they cannot afford additional watches or because the dress coordination issue is not important to them, for others, one particular watch cannot possibly be acceptable for numerous different styles and levels of dress, from casual dress to business dress to formal dress, and furthermore, one watch is not likely to match particularly well with many different outfits within one of these dress categories.
The obvious solution, if one has the means, is to purchase numerous different watches for the different situations. Notwithstanding the differences in watches based on quality and design of the watch movement and of the casing and bracelet, the appearance of the watch face itself often has the most immediate visual impact.
This has led some innovators to make a watch changeable in appearance by having interchangeable watch faces. Numerous prior art patents, namely U.S. Pat. No. 4,660,992 to Paul et al., U.S. Pat. No. 4,796,240 to Stevens, U.S. Pat. No. 5,008,869 to Dweck, U.S. Pat. No. 5,018,118 to Ross, U.S. Pat. No. 5,168,479 to Lima, U.S. Pat. No. 5,787,055 to Alpert, U.S. Pat. No. 5,793,710 to Jacobi, and U.S. Pat. No. 6,118,735 to Li disclose watches with removable watch faces. One common feature and drawback with these prior art watches, is that when the watch housing is opened to allow access to the watch face, the hour, minute and second hands become exposed, and since they are very fragile there is a great likelihood that they will be damaged by anyone who is not a professional watchmaker working in a controlled environment. Thus, this kind of interchangeable watch face is not suitable for consumers to change a watch face by themselves.
In the above-listed prior art is an alternate approach for interchangeable watch faces, namely, to provide an opening in the form of a slit in the side wall of the watch casing, so that a watch face can be slid out of the casing through the slit, and a replacement watch face slid into the casing via the slit. Here, the watch face would be positioned parallel to and below the plane of the hands. In this kind of arrangement, there is typically a drive shaft extending from the watch movement perpendicularly upward to and fixedly connected to the hands. This drive shaft is usually a series of three concentric tubes which are very tiny in nature. In order to use a replaceable watch face that slides in from the side, such watch face needs to have a notch extending from a peripheral edge radially inward to the center, so that the watch face can be positioned to have the notch straddle the drive shaft as it is slid into place, as seen in prior art patents, U.S. Pat. No. 4,660,992, U.S. Pat. No. 5,793,710, and U.S. Pat. No. 6,118,735.
A still further variation in structure is seen in U.S. Pat. No. 5,751,667 to Nunes, where there is an outer crystal and an inner transparent panel below the hands; however, these transparent elements are separable to gain access to the chamber below to change the golf tees or other graphic display articles, so that the hands become exposed to damage.
The present invention seeks to provide an alternative solution to the problem of establishing different appearances for a single wristwatch in a simple, convenient, inexpensive manner which is also safe from risk and damage to the hands of the watch.
It is a first object of this invention to provide a wristwatch wherein the owner of a watch can alter the basic appearance of the watch by altering the watch face in a manner which does not risk damage to the hands.
It is a further object to provide a wristwatch where a watch face is removable, and new watch faces are replaceable in a position below the hands but visible through the transparent crystal while the hands remain protected.
It is a still further object to provide a wristwatch with a removable watch face where the hands are protected by encasing the hands between a sandwich of outer transparent crystal and inner crystal above and below the hands, respectively, where said outer and inner transparent panes are secured together by an outer perimeter casing, thus forming an integral unit or cartridge. In a preferred embodiment, this casing has screw threads on the bottom outer periphery or elsewhere for engagement with mating screw threads in a casing of such wristwatch, which casing includes therein the watch movement or drive mechanism, which is typically an electric motor with an output drive mechanism.
It is an additional object of this invention of providing a wristwatch with a removable watch face where the hands are within a removable cartridge or upper housing that includes an outer transparent crystal and an inner transparent pane, with the hands secured and protected between these two transparent elements.
It is a further object to provide a wristwatch with a removable watch face where the casing, which contains the movement, includes at its top a recess to receive the watch face and to receive and hold the cartridge containing the hands and crystal, and to allow coupling of the drive shafts fixed to the hands with the movement in the casing.
Since the casing which contains the watch movement includes a laterally extending adjustment stem, the cartridge containing the hands and the outer crystal and inner glass can be attached to the housing by merely rotating it in the recess until the mating threads engage and become secured to each other. The rotation causes no interference of any parts because the drive stems simply engage with the drive shaft from the movement and are free to rotate in the lower transparent pane of the cartridge. Thereafter, the time is set by the adjustment knob.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.